The invention is based on a tire-pressure regulating system for automatically regulating the pressure of vehicle tires. A tire-pressure regulating system of this kind is known (German Auslegeschrift No. 27 36 603). In regulating systems of this kind, there is the problem that the tire-pressure control valve, disposed on the vehicle wheel, must be opened both when the tire is filled and when the tire pressure is being reduced, and it cannot assume its closed position until the pressure in the supply line has dropped below 1 bar. Usually, then, the supply line is evacuated whenever the tires are not being filled or whenever the tire pressure is not being reduced, so that the rotor devices which provided a rotary line connection to the wheels are relieved of pressure, in order to attain the lowest possible amount of friction.
A tire-pressure control valve is already known from German Offenlegungsschrift No. 26 30 511, which is embodied as a slide valve. A slide valve of this kind is expensive, inconvenient, bulky and heavy. Its weight and its eccentric disposition on the tire produce a substantial imbalance, which impairs the performance of the tire during vehicle operation. Such a valve also has substantial hysteresis, and it is susceptible to soiling by material worn off from the tire.